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domm-tem3

Edit 0 27 …

Bridge Weight and Types of Bridges.

Broad Question: What bridge can hold the most weight?


Specific Question: Will an Arch, Suspension, or Beam Bridge hold more weight?


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http://www.cement.org/newsroom/2006_bridge_winners.asp http://home.comcast.net/~bygonebyways/kansas_66.htm


http://commons.wikimedia.org/wiki/File:Clifton_Suspension_Bridge_c1900_2.jpg

Variables

Independent Variable: Bridge Type

Dependent Variable: Average Weight Held (lbs.)


Variables That Need To Be Controlled: Same (except for the wires for suspension bridge), Same testing tool, Same environment.

Hypothesis

I hypothesize that the Suspension Bridge will hold the most weight, Followed by the Arch Bridge and then the Beam Bridge.

Graph of Hypothesis

Doms_Science8.JPG


Experimental Design

I am conducting an experiment that asks whether an Arch, Suspension, or Beam bridge will hold up more weight. I will be holding my experiment in the Technology Lab. I will only have one extra person besides me. That person will be the photographer. I will be the one building the bridges and recording the data. When I use the weight tester there will be an adult supervising me. I will only need three trials in order to get, a reliable conclusion to the experiment.

I will be recording my data on a printed out Spreadsheet/Data Table. I plan to document my progress with a photographer. They will use digital camera. I will then send the photographs to my science teacher and also print them out at home. I will then have photos on my wiki and on my display board.


Materials List


  1. Flat surface (counter or clipboard)
  2. Pencil
  3. copy of spreadsheet
  4. camera
  5. wood
  6. cable (for suspension bridge)
  7. weight testing tool
  8. One other person (photographer)
  9. tools for building


Procedure


  1. Go to safe environment
  2. Have a hammer, nails, weight testing tool, and wood ready.
  3. Start building the Arch bridge.
  4. When done, test with a weight testing tool.
  5. Record data.
  6. Repeat steps 4-5, two more times with arch bridge.
  7. Start building the suspension bridge.
  8. Repeat steps 4-6, but with the Suspension bridge.
  9. Start building the Beam bridge.
  10. Repeat steps 4-6, but with the Beam bridge.

Background Research

The cables and ends of a Suspension Bridge produce tension. The Columns produce compression.

The Golden Gate Bridge was finished on May 26, 1937. It w
as first opened to pedestrians on May 27, 1937. The next day it opened to drivers as well. It was a very difficult assignment. It started in December of 1928.

Arch Bridges have been around for 2000 years. The design makes it so that the underneath part of the arch has no tension on it.

Beam Bridges are normally made out of steel or reinforced concrete. The concrete can either be reinforced, prestressed, or post-tensioned.

References

Ball, Jackie, et al. Structures. Milwaukee, WI: Gareth Stevens Publishing, 2003. Print.

"How Bridges Work." How Stuff Works. How Stuff Works, Inc, 2012. Web. 18 Jan. 2012. <http://science.howstuffworks.com/engineering/civil/bridge5.htm>.

"How Bridges Work." How Stuff Works. How Stuff Works, 2012. Web. 19 Jan. 2012. <http://science.howstuffworks.com/engineering/civil/bridge3.htm>.

Sullivan, George, et al. Built To Last. New York: Scholastic, 2005. Print.

Results

Data Table


domm_tem3_resultsgraph.JPG




Photos

100_0233.JPG100_0232.JPG 100_0235.JPG 100_0239.JPG 100_0238.JPG 100_0236.JPG


Data Analysis

Conclusion



The original purpose of this experiment was to see which bridge (Suspension, arch, or beam) could hold the most weight. The results of this experiment were that the arch bridge held the most weight. It held an average of 70 lbs. The lowest weight held was by the beam bridge with an average of 23.33 lbs. The suspension bridge’s average weight was 41.67 lbs. On all the tests the beam ridge stayed in the 20 lbs range. The suspension and arch bridge were not consistent at all.


Discussion



My hypothesis was that the suspension bridge would hold the most weight, followed by the arch bridge and then the beam bridge. My results do not support my hypothesis. There is a relationship with the independent (Bridges) and dependent (weight held) variables. There are no patterns or trends in my data except for the beam bridge staying in the 20 lb. range.
I think that the tests did not go smoothly. I did not remember to do everything I had to and the bridges kept falling apart. If I could improve my experiment I would do everything I needed to on time and right. An interesting future study would be that we build the bridges bigger and stronger, to see if that would change anything.